[en] The attenuation of Longitudinal ultrasonic waves has been measured in single crystals of indium (99.999%) and of indium doped with 0.003 a % of tin in the intermediate state over the frequency range 10--30 MHz. Two phase have been identified in the superconducting layers. The fundamental frequency for one phase is approximately constant in both the specimens for the same field, but increases appreciably with the increase in the magnetic field from 0.7 H/sub c/ to 0.9 H/sub c/; the ν₀ value for the other phase, on the other hand, increases with increase in the concentration of the dopant and is independent of the magnetic field. The orgin of the two phases is discussed

[en] A Cu–2.5%Sn alloy was fabricated by continuous unidirectional solidification (CUS). The EBSD was used to analyse the microstructure of CSU Cu–2.5%Sn alloy. The results show that the alloy is composed of coarse columnar grains, which grow along the direction of [001] and [101], and the average diameter of the columnar grains is about 470 μm. Most of grain boundaries between the columnar grains are small-angle and the rest are high-angle grain boundaries. It is also found that the CUS Cu–2.5%Sn alloy has strong {110} <110> texture and cubic texture. (paper)

[en] The thin films of In₂O₃:Sn (ITO) were obtained by reactive evaporation method with ionized oxygen. The properties of films were investigated as function of substrate temperature. The electric properties are characterized by Hall Effect. For optical analysis were done transmittance measures, and the crystallinity were analysed by electron diffraction technique. (C.G.C.)

No abstract available

[en] Cubic boron phosphide, BP, is notorious for its difficult synthesis, thus preventing it from being a widely used material in spite of having numerous favorable technological properties. In the current work, three different methods of synthesis are developed and compared: from the high temperature reaction of elements, Sn flux assisted synthesis, and a solid state metathesis reaction. Structural and optical properties of the products synthesized from the three methods were thoroughly characterized. Solid state metathesis is shown to be the cleanest and most efficient method in terms of reaction temperature and time. Synthesis by Sn flux resulted in a novel Sn-doped BP compound. Undoped BP samples exhibit an optical bandgap of ∼2.2 eV while Sn-doped BP exhibits a significantly smaller bandgap of 1.74 eV. All synthesized samples show high stability in concentrated hydrochloric acid, saturated sodium hydroxide solutions, and fresh aqua regia . (paper)

No abstract available

[en] It has already been established that, by using a resonant detector in Moessbauer spectroscopy, the minimum spectral linewidth is 1.46Γ. Here Γ is the linewidth of the Moessbauer excited-state nuclear level. It is well known that the minimum linewidth obtained in conventional Moessbauer experiments is 2Γ. The quantum mechanical calculation using a nuclear-resonant detector, which predicts this result, is summarized. The fundamental equations describing the system are solved in the frequency domain and applied to the experimental results. The experimental results using the resonant-detector Moessbauer technique and an Sn-doped SiO₂ sample are presented. The best fit to the data is obtained using the resonant-detector quantum mechanical theory.

[en] Because Inconel 718 represents a major use of columbium and a large potential source of columbium for aerospace alloys could be that of columbium derived from tin slags, the effects of tin additions to Inconel 718 at levels which might be typical of or exceed those anticipated if tin slag derived columbium were used as a melting stock were investigated. Tin was added to 15 pound Inconel 718 heats at levels varying from none added to approximately 10,000 ppm (1 wt%). Limited 1200 F stress rupture testing was performed at stresses from 68,000 to 115,000 psi and a few tensile tests were performed at room temperature, 800 and 1200 F. Additions of tin in excess of 800 ppm were detrimental to ductility and stress rupture life

No abstract available

[en] The volume diffusion of ₅₁Cr in Zr-Sn alloys was measured in coarse-grained polycrystals, using the ''thin film'' method. The Sn content in the alloys ranged from 0.39 to 6.7 at%. In the ß-phase, diffusion temperatures were between 982₀C and 1240₀C. Sn was found to reduce the ₅₁Cr diffusion in the ß-phase, the effect being small but well defined. The linear dehancement coefficient b and its temperature dependence were calculated, assuming the formation of Sn-Cr dimers. For the more dilute alloys Q and D⁰ were determined and upon application of the Zener theory for D⁰, a negative contribution to the activation entropy was found. In the α-phase where three experiments were done at different temperatures, ₅₁Cr was shown to be a very fast-diffusing solute. No definite correlation with the Sn content was found probably owing to the anisotropy of the α-phase. (orig.)